The study of simple atoms and molecules permits unique confrontations - tweenfundamentaltheoryandprecisionmeasurements.Ithasplayedacentral role in many early discoveries that laid the foundations of quantum physics. Since computational and experimental tools are still evolving rapidly, intri- ing opportunities for future research continue to emerge. How could precision measurements uncover limits of the standard model? Howcanweimprovetheaccuracyoffundamentalconstants?Arefundamental constants really constant? How could we detect possible di?erences between matter and antimatter? How can we overcome the problem of hadronic str- ture in precision tests of quantum electrodynamic theory? How well can QED predict the energy levels of atoms with few electrons? What new physics can be discovered in experiments with exotic atoms? How well do we understand simple molecules? These are just a few of the questions that are now moving into a new focus. This volume collects contributions from experts at the frontier of atomic and molecular precision physics. It illustrates the current state of the art, points at future opportunities, and emphasizes an exciting frontier in atomic and molecular physics that remains as important as ever despite severalother strong currents and fashions in the ?eld. Since I have devoted more than three decades of my career to precision laser spectroscopy of the simple hydrogen atom, I am particularly grateful to the editor, Dr Savely G. Karshenboim, for his initiative to highlight such precision studies of simple atoms and molecules.